Aromatase Inhibition and Capecitabine Combination as 1st or 2nd Line Treatment for Metastatic Breast Cancer - a Retrospective Analysis

Background: Preclinical studies have shown that the combination of an aromatase inhibitor (AI) andcapecitabine in estrogen receptor (ER)- positive cell lines enhance antitumor efficacy. This retrospective analysisof a group of patients with metastatic breast cancer (MBC) evaluated the efficacy and safety of combined AIwith capecitabine. Materials and
Methods: Patients with hormone receptor-positive metastatic breast cancertreated between 1st January 2005 and 31st December 2010 with a combination of capecitabine and AI wereevaluated and outcomes were compared with those of women treated with capecitabine in conventional dose orAI as a monotherapy.
Results: Of 72 patients evaluated, 31 received the combination treatment, 22 AI and 19capecitabine. The combination was used in 20 patients as first-line and 11 as second-line treatment. Mean age was46.2 years with a range of 28-72 years. At the time of progression, 97% had a performance status of <2 and 55%had visceral disease. No significant difference was observed between the three groups according to clinical andpathological features. Mean follow up was 38 months with a range of 16-66 months. The median PFS of first-linetreatment was significantly better for the combination (PFS 21 months vs 8.0 months for capecitabine and 15.0months for AI). For second-line treatment, the PFS was longer in the combination compared with capecitabineand Al groups (18 months vs. 5.0 months vs. 11.0 months, respectively). Median 2 year and 5 year survival didnot show any significant differences among combination and monotherapy groups. The most common adverseevents for the combination group were grade 1 and 2 hand-for syndrome (69%), grade 1 fatigue (64%) andgrade 1 diarrhoea (29%). Three grade 3 hand-foot syndrome events were reported.
Conclusions: Combinationtreatment with capecitabine and AI used as a first line or second line treatment was safe with much loweredtoxicity. Prospective randomized clinical trials should evaluate the use of combination therapy in advancedbreast cancer to confirm these findings.